DOC: Web-site release notes, and some updates on front page.

I would write something a bit less direct. Look for example what I put in the g+ page. Here is a suggestion.

Dipy_ is a **free** and **open source** software project for
**diffusion** *magnetic resonance imaging* (dMRI) **analysis**. The goal of Dipy is to accelerate progress in dMRI beyond any known standards and become a paradigm for medical imaging. For this reason, we often start working in  problems in diffusion that end up being useful in much larger communities. Look for example to our extraordinary multimodal diffeomorphic registration module implemented completely in Python and Cython.




Dipy is a free and open source software project focusing primarily on diffusion magnetic resonance imaging (dMRI) analysis. However, today Dipy brings solutions way beyond the realm of dMRI for example using its state-of-the-art multimodal registration mechanisms.